STETJCTTKE OF GLANDS. 



thicker, and then they run quite parallel to one another to 

 their termination (fig. 262). 



[ 425. Among the whole of the vertebrata, the parts which 

 are the efficient agents of 

 secretion in the liver are 

 so intimately connected 

 into a compact and little 

 lobular organ, by means 

 of the vessels and cellular 

 substance, that it is ex- 

 tremely difficult to form a 

 proper notion of its struc- 

 ture. Perhaps the follow- 

 ing is the true account of Fi S- 263. A, four lobules from the 



the structure of the liver, Uver f a * uman sul f ct f^* * a ? e ' 

 , <? M -i magnified twice ; a branch of the hepatic 



when fully formed m man vein> a> rece ives a more minutely ramified 



twig from each lobule. B, some of the 

 cells of which the lobules of the liver are 

 composed, seen under a magnifying power 

 of 200 ; in the greater number the clear 

 nucleus is apparent. 



B 



It 



and the mammalia 



is easy to obtain convic- 



/ 



tion of the fact, that the 

 ends of the secreting parts 

 of the liver are leaf-like 

 lobules with blunt projec- 

 tions, which, in prepara- 

 tions of the organ, are 

 most apt to remain at- 

 tached to the minute ve- 

 nous twigs (fig. 263, A, a, 

 and 264, a, b, b). These 

 lobules are composed of 

 compact angular and 

 rounded cells (fig. 263, 

 B) Betwixt the several di- Flg - 264 '~~ a ' a branch of the hepatic 



JJ / J-*\_/ V IT A-.W L 1 ^ ij\s V V-l CdjL. V1.X , i ,f j_ ! j / i -i ! -i 



/ . ^ * Xl vein with the tributary twigs of which the 



visions of the cells of the lobules of the liver are connected, as leaves 

 individual lobules, the are with the final branches of a tree. The 

 branches of the gall-ducts venous ramuscles (vencs intralobulares) lie 

 penetrate (fi* 266) and t ^ ie m iddle of each lobule, as is seen in 

 there form anastomosing the two next succeeding figures which re- 

 , . , , . present transverse sections of the hepatic 



retes, which surround sin- lobules magnified. After Kiernan. 

 gle groups of cells like 



islets. Some observers describe the final ends of the secreting 

 element of the liver of mammals as hollow acini or vesicles 



